A colonoscopy is a colon and rectum exam that's used to determine the cause of abdominal pain, chronic diarrhea or chronic constipation. It's also used as a screening test for colon cancer. While this test is important, it has a bad reputation. Fortunately, if the idea of having a long colonoscope inserted in your rectum makes you anxious, there's another option. Here are five things you need to know about virtual colonoscopies.
What are virtual colonoscopies?
Virtual colonoscopies are imaging tests that examine your colon and rectum. Unlike with traditional colonoscopies, no colonoscope is used. Instead, a CT machine will be used to take pictures of your colon and rectum. Virtual colonoscopies are also called CT colonoscopies since they make use of CT machines.
How are virtual colonoscopes performed?
Virtual colonoscopies are fairly simple and should only take about 15 minutes. You'll be asked to change into a medical gown, and then you'll lie on a table inside a CT machine. Once you're in place, your doctor will insert a small tube into your rectum and fill your colon with either carbon dioxide or air. This tube is smaller than a colonoscope, so while you may feel awkward, you won't feel physical discomfort. Filling the colon with air is important because it allows your doctor to examine the walls of the colon more easily.
You'll need to roll into different positions during the exam so that multiple angles can be captured by the imaging test. Expect to lie in a prone (face down) and supine (face up) position, but you may also need to lie on your side or assume other positions.
Once the images have been taken, the machine will compile them into 3D images. Your doctor will then examine these images for signs of polyps, cancer or other internal problems.
Do virtual colonoscopies require preparation?
The inside of your colon needs to be completely empty for a standard colonoscopy, and the same is true for virtual colonoscopies. This is because if there's any residue inside your colon, the CT machine won't be able to get a good look at the walls of your colon.
The day before your virtual colonoscopy, your doctor will tell you to follow a special diet. Generally, this diet restricts you to only clear liquids, like tea or broth. Red liquids, like cranberry juice or red sports drinks, should be avoided because they can look like blood during the test.
You may be told to perform additional steps. Your doctor may tell you to take a laxative pill the night before your test to make sure that your colon is completely clean. If you're having trouble emptying your colon before the test, you may need to perform an enema.
Are virtual colonoscopies effective?
Studies have reported that virtual colonoscopies are just as effective as standard colonoscopies. Virtual colonoscopies have been shown to be highly accurate in detecting colon polyps of that are 6 mm or larger. This is true for people of all age groups, so if you feel uncomfortable with the idea of a standard colonoscopy, you can safely opt for a virtual colonoscopy.
Are virtual colonoscopies safe?
Standard colonoscopies are associated with complications like colon tears or bleeding, but fewer complications are associated with virtual colonoscopies. You'll be exposed to radiation during your virtual colonoscopy, but this radiation level is low and the risk of developing cancer as a result is very low. In fact, the risk of fatal cancer per scan is only 0.04%.
If you need to have a colonoscopy done, ask your doctor if a virtual colonoscopy is right for you.